Well-drilling bit



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J. D. PACE WELL DRILLING BIT Filed May '7, 1921 ATTORNEY WITNESSES ww zflbz w nsane? @FIFHCCE.

JEFFEN navzs men, or snanvnroa'r, Louisiana.

WEL artners err.v

Application filed May 7;

To all whom it may concern:

Be it known/ that I, JEFFERSON LD. PACE, a citizen of the United States, residing at Shreveport, in the parish of Caddo and State of Louisiana, have invented new and useful Improvements in Well-Drilling Bits, of which the following is a specification.

This invention has reference to welldrilling bits, and its object is to provide a bit for the expeditious forming of deep wellv bores, especially oil well bores, and at the same time enabling the operator to obtain samples of the formation being drilled in order that its character may be ascertained.

In accordance with the invention, there is provided a rotary shoe so arranged that the main drill pipe may be screwed into it, the other end of the shoe being formed with circular series of teeth or cutters. The lower end of the shoe is closed except for the presence of a central hole to receive a testing or core barrel and through the closed end there is formeda number of holes so that water may pass down the inside, of the drill pipe about the core barrel and through the holes to the exterior of the drill pipe and there escape upwardly. The core pipe is provided with a gravity valve which will automatically close down tight and automaticall holds the core in the core, barrel when raising the drill to examine the core. The arrangement is such that water does not come in contact with thecore, thereby overcoming certain difliculties which have been experienced with other arrange-- ments for obtaining samples of the many formations encountered in putting down wells.

- The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming part of this specification, with the-understanding, however, that the invention is not confined to any strict conformity with the shown of the drawing, but may be changed an modified so long as such changes and modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawing:

Fig. 1 is an elevation ,of the rotary shoe and the lower end of the drill pipe to which the shoe is attached.

Fig. 2 is a longitudinal diametric section I of the structure shown in Fig. 1, but broken 1921. Serial no. teases.

intermediately to indicate that'the showing of Fig. 2 is much more extensive than the showing of Fig. 1.

Fig. 3 is a bottom plan view of the structure shown in Fig. 1.

Fig.4 is a section on the line 4-4 of Fig. 2. Fig. 5 is a fragmentary view of the upper end of the core 'pipe showing the valve lifted. t Fig. 6 is a section on the line 6-6 of Fi 5.

fi eferring to the drawing, there is shown a hollow drill pipe 1, provided at the lower end with a screw-thread 2 to receive a drill shoe 3 suitably threaded to correspond to the screw-thread 2. The shoe 3 has at one end, the upper' end, a socket to receive the hollow rod or drill pipe 1 and the parts are so proportioned that the end of the shoe remote from the socket provides a head 4 of suitable thickness not only to withstand the ,work to which it is sub 'ected but toprovide room for the formation of cutting teeth 5 arranged in circular series. These teeth, in the showing in the drawings, are right hand teeth.

Extending through the head 3 in the direction of the length thereof, is a series of passages or perforations 6 communicating with the interior of the pipe 1 through the head 4, and close to the throats of the teeth.

Thehead is provided with a threaded passage which receives the threaded lower end 7 of a core barrel 8 rising up in the pipe 1 to a desired height, leaving ample space about the core barrel. At the upper end the core barrel is provided with a valve 9 having a laterally expanded head 10 of a size to close the upper end of the core barthe upper end of the core barrel, but per- Y emitting a considerable movement of the valve lengthwise of the core barrel, and also permitting communication between the interior of the valve 9 and the interior of the drillpipe.

The core barrel'is provided "at the lower end witha short section 8 which is screwed into the threaded passage of the head 4and terminates in an outwardly beveled cutting edge 14 allowing the core to rise in the core barrel as the drilling proceeds. Between the section 8 -and the bottom of the main section of the core barrel is a core support ing ring 14, having a smaller internal diameter than the section 8 and barrel 8, but there rounded and loose in the barrel so as to readily rotate therein independently thereof. y V

In order to dispose of the chips and other debris as the drilling is performed,

water is forced down through the drill pipe core, will escape through the upper valve end ofthecore barrel through the slots of the valve 9 and the valve will readily drop by gravity onto the upper end of the core barrel whenever the pressure within the core barrel drops to a sufficient degree.

When the drill rod or pipe is raised for the purpose of removing and examining the core, the valve at once closes and water which may be in the drill pipe escapes through the holes 6 without affecting the core itself. The gravity Valve .9 is so con- I structed as to close air-tight when the pipe Core.

1 is being raised, thereby holding the core by suction from dropping out of the pipe.

This produces a simple and efficient ar rangement for the purpose, far superior to core barrel valves held closed. by springs.

The inner end of the cutter section 8 is spaced from the lower end of the core barrel and said space'forms a seat for the rotatable ring 14?, which is of smaller internal diameter than'the cutter section orthe core barrel, and serves to hold'the core in the barrel when once above the ring, and

also prevents binding and buckling of the The section 8 forms a cutterwhich extends below the lower ends of the openings 6, so that the water passing through 'said holes does not reach the core.

What is claimed is: a

1. In a well drilling tool, a rotary hollow drill pipehaving a terminal shoe body with cutting teeth on the lower end and passages therethrough for the outflow of water, said shoe body having a central core opening, and a core barrel secured therein and rising above the shoe body within the drill pipe, said core barrel having a check valve at its upper end preventing passage ofwater into the barrel, a cylindrical cutter section secured to and extending downwardly from the. shoe body in alinement with the core barrel and terminating in an annular cutcarried by. the shoe and open at its lower end, said core barrel extending upwardly from-the shoe into the drill pi e and provided at its upper end with a slidable valve having an expanded head ich constitutes a closure for the upper end of the core barrel, and an extension for said core barrel extending downwardly from the shoe and provided with a cylindrical cutter extending to the bottom of the cutting teeth of the shoe, said valve and cylindrical cutter cooperating to prevent water from entering the core barrel. 3. In a. rotary well drilling tool, a tubular pipe having a shoe secured to its lower end said shoe terminating in a circular series of cutting teeth, a core barrel carried by and extending upwardly from the shoe concentric with the pipe, said core barrel being open at its lower end, means extending from the shoe and engageable with the soil formation to exclude water from the lower end oi the barrel while drilling, said barrel being provided at its upper end with a longi-' tudinally movable valve having a laterally expanded head to close the barrel against access of water through the upper end, said valve having longitudinally-extended slots for the passage of a retaining pin permitting the opening of the valve and preventing its escape from the core barrel, said slots extending above the top of the core barrel when the valve is raised to permit escape of the air from the interior of the barrel.

4. In a well drilling tool, a hollow drill pipe, a'one-piece shoe with a screw socket into which the lower end of the pipe is screwed, said shoe having a circular series of cutting teeth at its lower end and provided with passages for the outflow of water, a core barrel concentric with and extending upwardly-from the shoe into the hollow drill pipe and provided at its upper endwith a gravity valve, means for retaining the valve in the core barrel with a limitedlongitudinal movement, and means extending below the shoe in alinement with the barrel and engageable with the soil formation being out, said means together with the valve serving to exclude all water from the interior of the barrel while permitting the escape of air therefrom.

5. A rotary drilling tool comprising a hollow drill rod, a shoe carried by the lower end of the rod and provided with cutting teeth at its lower end, a core barrel carried by and extending upwardly from theshoe within the drill rod, a cutter section extende ea? ing downwardly from the shoe to substancore barrel having its lower open end,

tially the same depth as the teeth on the screwed into said threaded passage upon one 20 shoe and constituting a continuation of the side of the head, a core cutter screwed into core barrel, the lower end of the core barrel the threaded passage upon the other side and the upper end of the cutter section formof the head and having a cutting edge ex-= ing spaced shoulders defining a cylindrloal tending substantially to the same de th as space enclosed by the shoe body, and a ring the cutting teeth on the shoe, the a jacent 25 freely and independently rotatable in said ends of the core cutter and core barrel being s ace and of smaller internal diameter than spaced from each other to form a seat in the t e core barrel whereby to sustain the core passage, a rotatable ring having a smaller and to prevent binding and buckling of the internal diameter than the core barrel or same. core cutter and mounted in said seat and 30 6. A rotary drilling tool comprisinga holadapted to guide and retain the core in the low drill rod, a shoe carried by the lower core barrel.

end of the drill rod and provided with In testimony, that I claim the foregoing cutting teeth on its lower end, and a head as my own, I have hereto afixed my signaat an intermediate point, said shoe having ture.

a central threaded passage therethrough, a JEFFERSON DAVIS PACE. 

